微生物群落有工作記憶，可以把它們變成活的計算機

微生物群落有工作記憶，可以把它們變成活的計算機

Collections of bacteria known as biofilms can store memories of exposure to light, providing intriguing parallels to the way neurons process memories in our brains. This doesn't mean you need to be nice to bacteria lest they harbor a grudge, but it may prove useful for neuroscience research and making biological computers.

被稱為生物膜的細菌群可以儲存暴露在光下的記憶，這與我們大腦中神經(jīng)元處理記憶的方式有有趣的相似之處。這并不意味著你必須善待細菌，以免它們懷恨在心，但它可能對神經(jīng)科學研究和制造生物計算機有用。

Recent discoveries by Professor Gürol Süel of the University of California San Diego have helped promote renewed respect for bacteria, demonstrating they can communicate with each other in colonies using ion channels and even support each to share resources. Süel and others have also demonstrated bacteria can remember certain events, changing their response to circumstances based on what they have experienced previously.

加州大學圣地亞哥分校的Gurol Suel教授最近的發(fā)現(xiàn)幫助促進了對細菌的重新尊重，證明細菌可以通過離子通道在群體中相互交流，甚至支持彼此共享資源。Suel和其他人也證明了細菌可以記住某些事件，根據(jù)它們之前的經(jīng)歷改變它們對環(huán)境的反應。

Süel brings these two discoveries together in Cell Systems. Blue light has been found to alter the flux through cells' ion channels, so Süel's team spread Bacillus subtilis on a growth medium and illuminated them for five seconds with a fluorescent lamp. Using a mask of the University's logo, some of the bacteria were protected from the light, while others were fully exposed. Even hours later, the responses of the bacteria varied depending on whether they were shaded or not, with the exposed bacteria having more potential to transport potassium through their membranes.

Suel在細胞系統(tǒng)中把這兩個發(fā)現(xiàn)結合在一起。人們發(fā)現(xiàn)藍光會改變細胞離子通道的通量，所以Suel的研究小組將枯草芽孢桿菌(Bacillus subtilis)傳播到生長培養(yǎng)基上，用熒光燈照射它們五秒鐘。利用該大學標志的面具，一些細菌被保護起來不受光照，而另一些則完全暴露在陽光下。即使在數(shù)小時后，細菌的反應也會根據(jù)它們是否被遮蔽而有所不同，暴露在陽光下的細菌更有可能通過細胞膜運輸鉀。

Stephen Luntz

"When we perturbed these bacteria with light they remembered and responded differently from that point on," Süel said in a statement.

Suel在一份聲明中說:“當我們用光線干擾這些細菌時，它們的記憶和反應從那時起就不同了。”

When potassium availability was cycled on and off, the light-exposed bacteria produced the exact opposite response to those that had been shaded, closing their potassium channels when their counterparts were opening them. Feeding the bacteria glutamine restored them to their usual state. The researchers hope to put this to use, turning bacteria into a model for neurons.

當鉀的有效性循環(huán)時，暴露在陽光下的細菌產(chǎn)生的反應與那些被遮蔭的細菌完全相反，當它們的對手打開鉀離子通道時，它們卻關閉了鉀離子通道。給細菌喂食谷氨酰胺使它們恢復到正常狀態(tài)。研究人員希望利用這一點，把細菌變成神經(jīng)元的模型。

“For the first time we can directly visualize which cells have the memory,” Süel added. “That's something we can't visualize in the human brain."

“我們第一次可以直接看到哪些細胞有記憶，”Suel補充道。“這是我們無法在人腦中想象出來的東西。”

With suitable masks, bacteria could be turned into a circuit board, with some light-primed and others not, turning bacterial communities into a sort of computer. The team also found longer light exposures produced greater changes to membrane potential, suggesting outcomes could be more nuanced than simply whether a bacteria was primed or not. If varying intensity or wavelength of light produce different sorts of priming, then even more sophisticated devices may be possible.

有了合適的掩模，細菌可以變成電路板，有些可以發(fā)光，有些則不能，把細菌群落變成某種電腦。研究小組還發(fā)現(xiàn)，長時間的光照會對細胞膜電位產(chǎn)生更大的變化，這表明結果可能比簡單地判斷細菌是否受到了刺激更微妙。如果不同強度或波長的光產(chǎn)生不同種類的啟動，那么更復雜的設備可能成為可能。

"Bacteria are the dominant form of life on this planet," Süel said. "Being able to write memory into a bacterial system and do it in a complex way is one of the first requirements for being able to do computations using bacterial communities."

“細菌是這個星球上的主要生命形式，”Suel說。“能夠?qū)?nèi)存寫入細菌系統(tǒng)并以一種復雜的方式進行操作，是使用細菌群落進行計算的首要要求之一。”